Inhibitors of nitric oxide synthesis and TNF-alpha expression from Magnolia obovata in activated macrophages

Planta Med. 2000 Jun;66(5):469-71. doi: 10.1055/s-2000-8592.


Nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) are the major mediators produced in activated macrophages which contribute to the circulatory failure associated with septic shock. An activity-guided fractionation of an MeOH extract of stem bark of Magnolia obovata afforded two inhibitors of NO production in lipopolysaccharides (LPS)-activated macrophages by the suppression of i-NOS expression. Their structures were elucidated by spectroscopic methods to be magnolol and honokiol with IC50 values of 16.8 and 6.4 microM, respectively. They also inhibited the production of TNF-alpha in LPS-activated macrophages. Thus, these compounds may be possible candidates for the development of new drugs to treat endotoxemia accompanied by the overproduction of NO and TNF-alpha.

Publication types

  • Letter
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biphenyl Compounds / chemistry
  • Biphenyl Compounds / pharmacology*
  • Blotting, Western
  • Cell Line
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacology*
  • Lignans*
  • Lipopolysaccharides
  • Macrophage Activation
  • Macrophages / drug effects*
  • Magnetic Resonance Spectroscopy
  • Magnoliopsida / chemistry*
  • Mice
  • Nitric Oxide / antagonists & inhibitors
  • Nitric Oxide / biosynthesis*
  • Nitric Oxide Synthase / antagonists & inhibitors*
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors
  • Tumor Necrosis Factor-alpha / biosynthesis*
  • Tumor Necrosis Factor-alpha / metabolism


  • Biphenyl Compounds
  • Enzyme Inhibitors
  • Lignans
  • Lipopolysaccharides
  • Tumor Necrosis Factor-alpha
  • magnolol
  • honokiol
  • Nitric Oxide
  • Nitric Oxide Synthase